1. Field of the Invention
The present invention relates to multiple hopper rail cars and, more particularly, the present invention relates to a process of removing the center portion from a three-hopper 4,750 cubic foot capacity grain car and converting the rail car into a two-hopper 3,190 cubic foot capacity covered hopper rail car particularly suited for cement, aggregates, pearlite rock, ground slate and roofing granules.
2. Background Information
Covered multiple hopper cars of the type used to handle bulk shipments of particulate materials can be made in a wide range of sizes to accommodate different volumes of materials. However, in the interest of safety and to prevent overloading of tracks and bridges, limits are imposed on the gross loading of a rail car and its contents. Limits are also imposed on the overall height of a rail car and its load in order to keep the car""s center of gravity within a prescribed limit.
The density of a particular product to be transported by a rail car can vary widely from low density plastic pellets having a density of about 28 pounds per cubic foot, to grain with a density of about 35 pounds per cubic foot and on to aggregate such as sand, gravel and cement having a density of about 90-100 pounds per cubic foot. To maximize load sizing and the efficiencies of handling, it has been common to build rail cars for specific commodities so that a specific approximate tonnage of a particular commodity can be transported in a single rail car. Thus, four-hopper rail cars are often used for handling light products, three-hopper rail cars are used for handling grain and two-hopper rail cars are used for handling cement, sand and gravel. Alternatively, a rail car can be manufactured which has smaller or larger hoppers, depending upon whether it is being designed to handle a certain weight of a high-density material or a low-density material.
A hopper rail car can have a useful life of 30-50 years. Therefore, it can and does happen that the existing stock of all types of hopper rail cars might periodically be out of balance with the current needs of a nation""s economy.
This problem was addressed in my prior U.S. Pat. No. 4,696,237 (hereinafter xe2x80x9cmy ""237 patentxe2x80x9d), which is incorporated herein by reference. My ""237 patent discloses a converted covered dual hopper rail car which is made by converting a rail car having three covered hoppers suitable for carrying a large volume of relatively low density commodity to a rail car having two hoppers suitable for carrying a relatively smaller volume of a high density commodity. Specifically, as disclosed in my ""237 patent, this is accomplished by: internally bracing an interior portion of one end of one hopper end section; severing an unwanted center hopper section from the two end hopper sections; removing the unwanted section; and reassembling and welding the free sections to each other. My earlier ""237 patent discloses that the vertical cutting and welding is horizontally offset at the upper side plate, and the side sill to provide a tab and notch locking arrangement for reinforcement. My ""237 patent also teaches the need to provide roof loading hatches which are provided with downwardly extending collar portions which limit the maximum loading height within the converted hoppers.
My ""237 patent was specifically directed toward the conversion of a 4,427 cubic foot capacity covered hopper rail car into a 3,148 cubic foot capacity rail car. Unfortunately, 4,427 cubic foot capacity covered hopper rail cars are not currently readily available and the resulting 3,148 cubic foot capacity rail car may not offer a maximum carrying capacity. There are several other significant problems with the converted rail car and method of my ""237 patent. Most significantly, the outlets in the resulting car were not properly positioned, which then required adapters to be utilized at the unloading sites for the resulting converted rail car. The use of additional adapters makes the converted rail car somewhat impractical. Additionally, the assembly processing time associated with my earlier invention could be improved.
It is among the objects of the present invention to provide an improved converted hopper rail car suitable for carrying commodities such as cement, aggregates, pearlite rock, ground slate and roofing granules. It is another object of the present invention to provide an improved method of converting a multiple hopper rail car into a hopper rail car suitable for carrying commodities of a relatively heavy density. The foregoing and other objects and advantages are achieved by the converted hopper rail car and method of the present invention. In the present invention a center section of the multiple hopper rail car is completely severed and removed from a location between the two remaining end sections. The center section includes the entire center hopper section and a bulkhead portion of an adjacent end hopper section. The length of the removed center section permits the re-use of the center sloped sheets from the rail car. The remaining portions of the end hopper sections, which were located adjacent the removed center section, are then reassembled and welded together. As noted above, the removed center section includes the center hopper and the bulkhead portion of an adjacent hopper section such that certain extension members are added to the existing bulkhead prior to welding of the remaining sections or end hopper portions together. The present invention also replaces the outlet gates and changes the slope of certain bottom sheets to properly position the outlet gate. The present invention positions the cut line of the side sheets such that the side stakes are adjacent the welded splice connection and the splice connection is reinforced.
These and other advantages of the present invention will be clarified in the detailed description of the preferred embodiment taken together with the attached figures wherein like reference numerals represent like elements throughout.